Space missions management requires to cope with a number of different issues, among which the need of properly handling contacts among one or more ground antennae, and one or more satellites belonging to a space mission. The manuscript presents a planning approach designed to support the automatic allocation of contact opportunities among a set of ground stations and a set of satellites, with the aim of providing the most efficient configurations, in terms of contact time maximisation and compliance to the requirements. The optimisation strategy herein discussed builds upon the integration of techniques based on Genetic Algorithms, Graph Theory, and Linear Programming, in order to output the optimum, or sub-optimum, scheduling plan. Simulations show that the integration of such techniques allows to generate conflict-free and high-performance solutions to the scheduling problem.